[Coco] MPI 2D rendering

[RETRO Innovations]

On 3/28/2015 1:50 PM, Gene Heskett wrote:
>
> On Saturday 28 March 2015 14:39:03 RETRO Innovations wrote:
>> For those who care, I've sent the MPI design off for prototype
>> manufacture.  Here is a view of the unit in more natural coloring:
>>
>> http://gerblook.org/pcb/5j7wfp8V8PJ5pt6BH8kNzQ
>>
>>    * Final boards will be blue or black, as I'm not a fan of green, but
>>      green is cheapest for a prototype.
>>    * Astute viewer will notice the larger board with the sockets is
>>      "upside" down.  This is by design, as a stencil will need to be
>>      created, and the front of the buffer board and the back of the
>> main board have the majority of the SMT items.  When the boards are
>> separated, it won't make any difference.
>>
>> Jim
> Looks good Jim.  Do patterns for a box exist yet?
Well, no, but here are the dimensions:

  * Overall (x*Y) =  3.85x6"
  * Assuming bottom left corner of board is 0,0, 10 .187" holes centered @
      o one column @ .275"
      o another @ 3.575" (dimension - .275", board pattern is symmetric
        in X dimension)
      o 5 rows @ 1.1", 2.25", 3.4", 4.55, 5.7"  (rows every 1.15")
  * As you can see from the pics, the standoffs define the size of the
    cart rectangle (1.1 + (.187/2) is the front of the first cart, and
    2.25"-(.187/2) defines the bottom of it.)
  * The carts are wider than the PCB, though, so plan accordingly for
    the width of the enclosure
      o Note that those are minimums for cart size.  Measure a cart to
        be sure, add some space, then subtract from the dimensions above
        to get "fit" amount.  Divide by 2 and subtract from dimensions
        above to get cut lines.
  * All connectors are at front (Y = 0) side:
      o DIN5 is centered at X=.35", Z=.375" above top of PCB (PCB is
        1.6mm in thickness).  hole diameter needs to be at least .55",
        but I would not recommend that, as the DIN plug thickness will
        be > 0.  CoCo uses .666" diameter holes
      o Mini USB is centered at X=3.3", with opening minimum of X=.303"*
        Z=155" with bottom of connector resting on top of PCB directly
        (1.6mm from top of standoffs).  I would highly recommend adding
        .01 to .02 to both dimensions for fit.
      o Coax is centered at X=3.65, but I do not have diameter or Z axis
        data on it yet.  I can find the datasheet if needed.
      o 80 conductor micro IDC cable needs to have a slot in the case
        about .3" above the top of the PCB plane in the Z axis, centered
        on the board (X=3.85/2), for the width of 2 IDE cables stacked
        on top of each other.

That should give you enough to create a mechanical drawing. If someone 
wants to create mechanicals, I've been itching to try out a light gauge 
steel enclosure option, and this might be a good candidate.  Obviously, 
all other things assumed working, this would require a few folks to 
consider it before we ran a batch.

Jim

>
> Cheers, Gene Heskett


-- 
RETRO Innovations, Contemporary Gear for Classic Systems
www.go4retro.com
store.go4retro.com